Oil separator for compressors



March 23; 1937. w. F. BORGERD OIL SEPARA TOR FOR COMPRESSORS "Filed March 13, 1936 Ill/6% 7* lzfiliarfi/Ffior qeraz 0f Patented Mar. 23, 1937 UNITED STATES.

OIL SEPARATOR FOR COMPRESSORS William F. Borgerd, Riverside, Ill., assignor to International Harvester Company, a corporation of New Jersey Application March 13, 1936, Serial No. 68,587

5 Claims. (01. 230-202) This invention relates to an oil separator for compressors. More specifically, it relates to an oil separator particularly adapted for separating lubricating oil from the refrigerant gas used by a compressor for refrigerators.

In some compressors for the household type of refrigerators, or for other refrigerators of small capacity, the evaporated gas is returned to the crank case of the compressor. In systems of this type a large amount of the lubricating oil is always entrained with the gas delivered into the compression chamber and the lubricant is, therefore, fed to the condenser. It is undesirable to carry the lubricant through the condensing system and through the evaporator. For that reason some compressors are utilized which attempt to keep the refrigerating gas separated from the refrigerating oil. There is, however, a certain amount of lubricant from the compressor cylinder walls which is picked up and carried with the compressed gas. This small amount tends to accumulate in the system unless means are provided to remove it.

The object of the present invention is to provide a simple effective separating construction for removing lubricating oil from the gas of a refrigerating system and for returning the lubricant to the crank case of the compressor.

Other more detailed objects will be apparent from the description which follows. In the drawing:

Figure 1 is avertical cross section through a compressor showing a built-in oil separator embodying the invention;

Figure 2 is an enlarged view of a portion of the section of Figure 1 to show more clearly the elements makingup the separator;

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Figure 3 is a side elevation of the oil separating baflles with a portion of the outer baffle wall cut away to show the inner battle in elevation.

As illustrated, an air cooled compressor of a con-.

ventional type has a crank case 10 adapted to be sealed as is conventional with compressors of this type against the escape of refrigerating gas. A cylinder N forms a compression chamber in which a piston I2 is reciprocated by a con-.

necting rod I3 driven from a crankshaft I4. The crankshaft |4 may be driven by any'source of power. A cylinder head I 5 contains a springpressed discharge valve l6 which will not be described indetail, as it does not form a part of the present invention. The valve I6 controls passage of gases from the compression chamber through a discharge passage H in the head to-a discharge passage I8 formed in the upper end of the cylinder II. The compressed gas is 'then conducted by a fitting I9 and a conduit 20 to a suitable condenser.

A fitting 2| forms means for supplying low pressure gas supplied by a conduit 22 t a'conduit 23 formed in the cylinder block. The conduit 23 communicates with a vertical cylindrical chamber 24 formed in the cylinder block extending downwardly from the upper end. An oil drain conduit 25 -formed in the cylinder block provides a communication between the crank case In and the chamber 24. Said conduit is concentric with respect to said chamber.

Directly above the chamber 24 a chamber 25, somewhat:;larger in diameter, is formed in the cylinder head extending upwardly from the bottom surface thereof. A conduit 26 formed by a passage in the cylinder head provides communication between the chamber 25 and a valve chamber 21 formed in thecylinder head. An inlet valve 28 of the disk type is supported at the lower end of the valve chamber 21 by a retainer 29. This type of valve construction is in wide use on small compressors of this type. On the suction stroke, it falls against the retainer 29 to admit gases to the compression chamber. 0n the compression stroke, as illustrated, it is lifted against a seat 30 formed in the valve chamber to provide a seal against the escape of gases.

The oil separator construction, as best shown, in the enlarged view of Figure 2 consists essentially of an outer conical baflle 3 I, an inner conical baffle 32 spaced from the baffle 3|, and an oil receiving member 33. The conical bafiie 3| is fitted to the cylindrical chamber 24 abutting the edge which forms the upper end thereof. Intermediate its ends the upper portion of the baflle above contact with the upper wall in the cylinder block is imperforate. The lower end is provided with four apertures 34 formed with intu'rned flanges to facilitate draining of the separated oil down the conical wall without dripping into the path of gases flowing through the apertures. The lower end of the bafile 3| is restricted to a diameter substantially half that of the chamber 24. Said lower end extends-into the flared receiving end 35 of the oil return member 33. Said member is fitted into the upper end of the oil drain 25. Suflicient space is provided between the receiving end 35 and the delivering end of the baflle 3| to allow breathing or pulsating of the crank case without throwing oil from the oil drain. It should, however, be noted at this point that compressors of this type are usually constructed with two cylinders arranged on cranks at 180 degrees apart whereby pumping action in the crank case is. not an important factor.

The inner baflie 32, as previously pointed out, is spaced with respect to the outer baffl 3| to allow a passage annular in crosssection for flow of the incoming gases. The upper ends of the two baflies are connected by an annular sealing member 36. Near its upper end the baffle 32 is provided with a Series of elongated openings 31 provided with inturned flanges similar to the apertures 34 to allow draining of the separated oil downwardly along the bafile walls. To form an additional means for separating oil, a conical projection 38 5 concentric with respect to the baffies extends downwardly into the upper end of the inner baffle 32. Said projection is spaced from the sealing member 36 to provide for gas flow over said sealing member and into the outer portion of the chamber 25. Oil collecting on the projection 38 flows to the lower end and drops centrally through the baffles into the oil receiving portion of the inember'33.

The operation of the oil separator of this invention will be understood from the description given above. The compressor is operated drawing a pulsating current of gases to be compressed through the inlet conduit 22 into the separator chamber 24. As the gas impinges against the walls of the conical baflles 3| and 32, the entrained oil carried. by the gas collects on the baffle walls and is thereby moved from the gases prior to their delivery to the compression chamber. As the lubricant collects into larger drops, it flows 25 downwardly around thefianges of the openings 31 and 34 and drips off the ends of the conical bafiles into the receiving end 35 of the oil return member 33. It will be noted that the baffles and the associated parts are so constructed, as indicated by the arrows in Figure 2, that there is an appreciable volume of gases passing over the lower edges of the conical baffles. 'This is an important feature, as high velocity flow of gases over the edges 6f collecting bailies will entrain the collecting liquid and reduce the effectiveness of the separation.

It will be understood that applicant has shown and described only a preferred embodiment of his improved lubricant separating means for refrigerant compressors and that he claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is: v 1. In a refrigerant compressor the combination of a cylinder block formed with a lubricant separation chamber terminating at the upper surface of the block, an inlet conduit communicating with said chamber, an oil drain conduit communicating with said chamber at the lower end, two concentric conical baffles mounted in spaced relation .in the separation chamber and extending above the upper surface of the block, said baffies being formed with staggered openings, a cylinder head mounted over the block, said 5 head being formed with a recess surrounding the upper ends of the conical baffles to provide a space thereabove, and an inlet conduit forming a communication between the recess and the cylinder. 60 2. In a refrigerant compressorthe combination of a cylinder block formed with a lubricant separation chamber terminating at the upper surface of the block, an inlet conduit communicating with said chamber, an oil drain conduit 65 communicating with said chamber at the lower end, two concentric conical baflles mounted.in spaced relation in the separation chamber and extending above the upper surface of the block, said bailles being formed with staggered openings, 70 a cylinder head mounted over the block, said head being formed with a recess surrounding the upper ends of the conical baflies to provide a space thereabove, and an inlet conduit to the cylinder communicating with the recess.

3. In a refrigerant compressor the combination of a cylinder block formed with a cylindrical lubricant separation chamber terminating at the upper surface of the block, an inlet conduit communicating with said chamber, an oil drain conduit communicating with said chamber centrally thereof at the lower end, two concentric conical baffles mounted in spaced relation in the separation chamber and extending above the upper surface of the block, the outer baflie being seated around the edge of the separation chamber at the top of the block, an 011 return member mounted over the lower end of the outer baflie in spaced relation thereto and connected with the oil drain conduit, said baflles being formed with staggered openings and being sealed against the escape of gases between the two bafiies at the top thereof, a cylinder head mounted over the block, said head being formed with a recess surrounding the upper ends of the conical baflles to provide a space thereabove, and an inlet conduit to the cylinder communicating with the recess.

{1. In arefrigerant compressor the combination of a cylinder block formed with a cylindrical lubricant separation chamber terminating at the upper surface of the block, an inlet conduit communicating with said chamber, an oil drain conduit communicating with said chamber at the lower end, spaced concentricbatlles mounted in spaced relation in the separation chamber and extending above the upper surface of the block, an oil return member mounted over the lower end of the outer battle in spaced relation thereto and connected with the oil drain conduit, said baflles being formed with staggered openings and being sealed against the escape of gases between the two baflies at the top thereof, a cylinder head mounted over the block, said head being formed with a recess surrounding the upper ends of the conical bailles to provide a space thereabove, said head being provided with a conical oil return portion depending downwardly centrally of the conical battles and an inlet conduit to the cylinder communicating with the recess.

5. In a refrigerant compressor the combination of a cylinder block formed with a cylindrical lubricant separation chamber terminating at the upper surface of the block, an inlet conduit ..communicating with said chamber, an oil drain conduit communicating with said chamber at the lower end, two concentric conical baflles mounted in spaced relation in the separation chamber and extending above the upper surface of the block, anoil return member mounted over the lower end of the outer bailie in spaced relation thereto ans:

connected-with the oil drain conduit, said bafiies being formed with staggered openings and being sealed against the escape of gases between the two baffles atthe top thereof, a cylinder head mounted over the block, said head being formed WILLIAM F. BORGERD. 

